824
FXUS65 KBYZ 150817
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
217 AM MDT WED JUL 15 2026
KEY MESSAGES
- EXTREME HEAT WARNING CONTINUES FOR FAR SOUTHEAST MT TODAY, WITH
TEMPS NEAR 100 DEGREES FOR THE 6TH STRAIGHT DAY.
- FLASH FLOOD WATCH IN EFFECT THIS AFTERNOON INTO EARLY THURSDAY
FROM SHERIDAN TO MUSSELSHELL COUNTY AND WEST. SLOW MOVING STORMS
WILL BE CAPABLE OF PRODUCING 1"/HR OR GREATER RAINFALL RATES.
- ANOMALOUSLY HIGH MOISTURE REMAINS OVER THE REGION INTO THE
WEEKEND; DAILY CHANCE OF AFTERNOON/EVENING THUNDERSTORMS.
UPDATE
THE RISK OF HEAVY RAIN EARLY THIS MORNING HAS ENDED AND HAVE
CANCELLED THE CURRENT FLOOD WATCH WHICH WAS IN EFFECT TIL 3AM. A
WATCH REMAINS IN EFFECT FOR THIS AFTERNOON AND EVENING.
TRAILING AREA OF STRATIFORM RAIN IS LIFTING THRU NW ROSEBUD COUNTY
AND WILL EXIT OUR CWA IN THE NEXT HOUR OR SO. THERE REMAIN A FEW
SHOWERS NEAR BILLINGS AND RYEGATE BUT THESE TOO SHOULD DISSIPATE
SOON. THERE ARE LIGHT SHOWERS SPREADING NORTHWARD INTO PARK
COUNTY, AND AS THIS IS CLOSE TO THE MID LEVEL BAROCLINIC ZONE THIS
SHOWER ACTIVITY MAY LAST LONGER. LOOKING UPSTREAM TO OUR
SOUTHWEST, MAIN SHORTWAVE OF INTEREST IS IN SOUTHERN ID AND WILL
PROVIDE ASCENT FOR VERY WET CONVECTION AGAIN LATER TODAY, OVER A
LARGER AREA THAN WE SAW TUESDAY (STORMS YESTERDAY WERE UNABLE TO
DEVELOP FURTHER EAST AND SOUTH PER VERY WARM MID LEVELS). THE DAY1
RISK FROM SPC SHOWS A MARGINAL RISK OF SEVERE STORMS, WITH THE
RISK BEING WIND AS THE AIR MASS IS LOOKING VERY CONDUCIVE TO WET
MICROBURSTS. THEN OF COURSE THERE IS THE HEAVY RAIN/FLOODING RISK.
TODAY'S FLOODING RISK WILL INCLUDE BURN SCARS SUCH AS ROBERTSON
DRAW/EAST SIDE SOUTH OF RED LODGE, AND ELK ON THE EASTERN SLOPES
OF THE BIGHORNS.
TODAY WILL BE COOLER ESPECIALLY OVER THE WEST HALF OF THE CWA. IT
IS ALSO VERY HUMID W/ ANOMALOUSLY HIGH PWATS IN PLACE. WOULD NOT
BE SURPRISED TO SEE SOME EARLY MORNING FOG IN OUR WEST EARLY TODAY
AND THIS WILL BE SOMETHING TO WATCH. FOG IN JULY IS VERY UNUSUAL.
JKL
DISCUSSION
TODAY THROUGH MONDAY...
UPPER RIDGING WITH REPEATED SHORTWAVES OUT OF THE SOUTHWEST WILL
BE THE MAIN PATTERN THIS WEEK. HOT TO VERY HOT TEMPERATURES
CONTINUE TODAY, WITH AN EXTREME HEAT WARNING IN EFFECT UNTIL
MIDNIGHT TONIGHT FOR CUSTER, POWDER RIVER, FALLON, AND CARTER
COUNTIES. LOOK FOR HIGH TEMPERATURES ACROSS THE AREA IN THE UPPER
80S TO 100F (WARMEST IN THE EAST).
THE FOCUS CONTINUES TO TRANSITION TOWARDS A WARM AND MOIST SETUP
INTO THE WEEKEND, AS DEEP MOISTURE CONTINUES TO STREAM INTO THE
REGION FROM THE SOUTHWEST. EXCEPTIONALLY HIGH PRECIPITABLE WATER
VALUES ARE SHOWN BY MODELS AND ENSEMBLES. THIS WILL RESULT IN THE
THREAT FOR HEAVY TO VERY HEAVY RAINFALL WITH SHOWERS AND
THUNDERSTORMS THE NEXT COUPLE DAYS.
TODAY WILL BE SIMILAR TO TUESDAY, WITH SLOW-MOVING AFTERNOON
SHOWERS AND STORMS LASTING INTO THE OVERNIGHT HOURS. THE THREAT
FOR STRONG TO SEVERE THUNDERSTORMS IS LOW THOUGH, WITH WEAKER
INSTABILITY AND MINIMAL SHEAR. THE THREAT FOR EXCESSIVE RAINFALL
EXISTS ONCE AGAIN, WITH ANOTHER MARGINAL RISK INCLUDING AND WEST
OF A SHERIDAN COUNTY TO MUSSELSHELL COUNTY LINE. A FLASH FLOOD
WATCH HAS BEEN ISSUED FOR THESE AREAS FROM NOON MDT TODAY TO 3 AM
MDT THURSDAY. THE MOST LIKELY TIMING BASED ON THE MOST RECENT HI-
RES RUNS IS 2 PM MDT TODAY TO 12 AM MDT THURSDAY.
MODELS CONTINUE TO SHOW A STATIONARY FRONT DEVELOPING NEAR THE
DAKOTAS BORDER THROUGH WEDNESDAY EVENING. THIS LOOKS TO KEEP
SOUTHEASTERLY AND DRY FLOW INTO SOUTHERN MONTANA. RELATIVE
HUMIDITY VALUES WILL BE IN THE TEENS TO LOW 20S PERCENT. WINDS DO
NOT LOOK TO BE THAT STRONG SO THE NEED FOR FIRE WEATHER HIGHLIGHTS
IS LOW, THOUGH THE RISK FOR GRASS FIRES WILL BE ELEVATED.
ANOMALOUS MOISTURE AND UNSETTLED FLOW CONTINUES THROUGH THE
WEEKEND, WITH DAILY CHANCES FOR AFTERNOON/EVENING SHOWERS AND
THUNDERSTORMS ACROSS THE WESTERN AND CENTRAL AREAS. LOOK FOR HIGH
TEMPERATURES IN THE 80S AND 90S THROUGH THE WEEKEND.
MATOS/ARCHER
AVIATION
BREEZY WINDS OUT OF THE NORTH BEHIND A FRONT WILL CONTINUE THROUGH
THE EARLY MORNING HOURS. SCATTERED SHOWERS AND THUNDERSTORMS
DEVELOP THIS AFTERNOON, MOVING WEST TO EAST THROUGH THE EVENING.
WITH THIS, LOCALIZED HEAVY RAIN REDUCING VISIBILITY (LOCAL MVFR
TO IFR) AND ERRATIC WIND GUSTS OF 20 TO 40 KNOTS ARE THE MAIN
THREATS.
TS POTENTIAL TIMES:
KLVM: 20Z-02Z
KBIL: 23Z-03Z
KSHR: 00Z-05Z
ARCHER
PRELIMINARY POINT TEMP/POPS
TDY THU FRI SAT SUN MON TUE
-------------------------------------------------------
BIL 089 064/092 066/097 067/098 067/095 064/088 065/086
4/T 62/B 51/U 51/B 51/U 21/B 23/T
LVM 087 056/090 057/094 058/095 058/094 057/088 057/083
7/T 43/T 34/T 63/T 41/U 22/T 45/T
HDN 092 064/093 065/098 066/099 065/096 063/089 063/088
1/B 52/U 41/U 41/B 41/U 21/B 23/W
MLS 099 068/095 068/098 070/101 070/097 065/091 063/087
0/U 11/U 22/W 53/T 30/U 10/U 12/W
4BQ 099 068/094 067/098 070/101 069/096 065/090 063/085
0/U 11/B 21/U 22/T 51/B 21/B 23/W
BHK 101 065/094 063/095 065/099 066/095 061/088 057/084
0/G 00/U 11/U 23/T 41/U 11/U 01/B
SHR 092 062/091 061/096 062/097 062/093 059/087 059/085
2/T 55/T 53/T 24/T 44/T 33/T 45/T
BYZ WATCHES/WARNINGS/ADVISORIES
MT...FLOOD WATCH IN EFFECT FROM NOON MDT TODAY THROUGH LATE
TONIGHT FOR ZONES
29-34-42-56-57-64>67-138-139-141-169>173-235.
EXTREME HEAT WARNING IN EFFECT UNTIL MIDNIGHT MDT TONIGHT FOR
ZONES 32-33-36-37.
WY...FLOOD WATCH IN EFFECT FROM NOON MDT TODAY THROUGH LATE
TONIGHT FOR ZONES 198-199.
WEATHER.GOV/BILLINGS
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